Improvement in saw-mill carriages



UNITED STATES APATENT OFFICE.

IMPROVEMENT IN SAW-MILL CARRIAGES.

Specification forming part of Letters Patent No. 117,936, dated AugustS, 1871.

To all whom fit may concern:

Beit known that I, GEORGE SELDEN, of Erie, county of Erie, State ofPennsylvania, have invented certain new and useful Improvements inSaw-Mill Carriages,.of which the following is a full, clear, and exactdescription, reference being' had to the accompanying drawing makingpart of this specification, in which- Figure l is a perspective view ofa carriage embodying my improvements. Fig. 2 is a vertical transversesection; and Fig. 3 is a detached view of the I-rack stick, showing themanner in which it is spliced.

Similar letters of reference denote corresponding parts in all thefigures.

My invention relates to that class of carriages Which is usuallyemployed in connection with circular saws, the lo g being supported uponheadblocks mounted upon independent trucks, and connected with each.other at their front end by a girt or stringer in such manner that theycan be adjusted longitudinally thereon in order to accommodate logs ofvarying length, the rear ends ofthe head-block being' connected witheach other by means of the set-shaft employed for thrusting the kneeforward. The invention consists of certain features of constructionwhich will be hereinafter fully explained.

In the drawing, A A represent the sills or bedpieces upon which. thecarriage is supported. Sill A is provided with a l'lat track of theordinary description. B is a wrought-iron A-rail, the form of which isshown plainly in Figs. il and 2.' C C are the head-blocks, but, as theknees which move the log forward on them form no part of this invention,they are not shown in the drawing. Any

usual or desired form of knee may be employed. The front ends of thesehead-blocks are mounted upon trucks or chairs D provided with groovedwheels E adapted to run upon the track B. F F are dummies orsupplemental carrying-blocks, one at each end of the carriage, designedto support the ends of the log. G is an intermediate stiiening-block.This block is not so high at its front end as the dummies and thehead-blocks, and is not designed to sustain any portion ofthe weight ofthe log, but merely to strengthen the carriage. His a wrought-iron I-girt or stringer, serving the double purpose of adj ustably connectingthe head-blocks and dummies with each other and of furnishing a supportfor the cogged rack knees.

I, which is bolted to the lower flange of the girt, as at f1?, Figs. land 3. h are splicing-plates, by means of which the sections of girt Hare secured to each other. J J are hangers or pockets attached to thelower sides of the head-blocks and dummies. They are provided within-turnin g' lips j jl, which inclose and engage with the upper iian geot' girt H, thus forming a connection which will slide freely on thegirt, so that the blocks and dummies can be adjusted thereon, as thelength ofthe log may indicate, as will be readily understood withoutfurther explanation. The pockets attached to the head-blocks and centralsupporting-block are usually constructed as shown in Fig. 2-that is, thelip jl is made rem ovable and adjustable, being secured to the body ofthe pocket by a bolt or bolts, j?, one upon each side ot theblock. Bythis construction I am enabled to remove the gi rt without sliding itthrough these pockets, and can also clamp the blocks to it, as it isnecessary to do in order that the cogged rack may propel the carriage. Kare carrying-wheels, upon which the rear ends of the blocks and dummiesare mounted. L is a set-shaft similar to those gen erally employed inthis class of carri ages for operating the devices for actuating the Bypreference I provide the dummies with sleeves or elongated hubs l,through which the set-shaft passes, for the purpose of giving a longerbearing-surface,as the dummies, for the sake of lightness and strength,have their vertical walls made quite thin, and when desired theheadblocks may be provided with similar hubs, although, as they areusually built with double walls, it will not generally be foundnecessary.

I am aware that dummies have been employed in combination with the oldstyle of frame carriages, but in that construction they formed no partofthe frame-work, and bore no part in supporting it against th e rackingand twisting strain 5 whereas, in my carriage they not only support theends oi' the log, but form an integral part oi' the frame-work, andstitien and strengthen it materially, so much so that I have found itadvantageous to add a third one, placed between the headblocks, but notdesigned to bear any part ofthe log. These dununies also enable me touse amueh lighter girt and rack, as they shorten the distance betweenthe bearing-points. I do not, therefore, claim them broadly.

The use of the hollow wrought-iron track is also a great improvementupon the cast-iron track now in common use, because it can be rolled inalmost any desired lengths, and is not liable to be broken by theconcussion produced by rolling a log upon the carriage, and, owing toits being holloW,'the quantity of iron required for its oonstruction isnot so great as to make it too eXpensive.

The form of the I-girt adapts it particularly for combinationwith thehead-block and cogged rack, as it is very stili, to resist strainbothvertically and laterally, and can be spliced by means of the bars orplates, as shown, without interfering` with either bolting,` on the rackor sliding the blocks over any portion of its upper liange from one endto the other.

In ease the splice shown should not be sufficiently strong, the platesmay be made to extend from the upper to the lower iian ge, and the lipsof the pockets made shorter so as to pass the plates, as thisarrangement will not impair or ai'ect the eiciency of the pockets.

Having now described my invention, What I claim as new, and desire tosecure by Letters Patent, is

l. In combination With the head-blocks C U,

`the I-girt H, pockets J, and rack I, substantially as set forth.

2. In combination With the head-block C, rack and string-er H, andset-shaft'L, the dummies F, substantially as set forth.

GEO. SELDEN.

Witnesses:

W. J. F. SIDDELL, F. F. CLEVELAND.

